Abraham, J, Ng, R, Morelato, M, Tahtouh, M & Roux, C 2021, 'Automatically classifying crime scene images using machine learning methodologies', Forensic Science International: Digital Investigation, vol. 39, pp. 301273-301273.
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Bowman, S, Casares-de-Cal, M-Á, Alvarez-Dios, J, Gomez Tato, A, Roffey, P, Richardson, A, McNevin, D & Gahan, ME 2021, 'Identification of Bacillus and Yersinia species and hoax agents by protein profiling using microfluidic capillary electrophoresis with peak detection algorithms', Australian Journal of Forensic Sciences, vol. 53, no. 1, pp. 2-15.
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© 2019, © 2019 Australian Academy of Forensic Sciences. Bacillus anthracis and Yersinia pestis are biological agents that pose an increasing concern to national security if deliberately disseminated. Hoax agents, including suspicious white powders and environmental bacterial species, can also cause disruption. In either scenario it is of high importance to rapidly and accurately identify any suspicious powder as hazardous or hoax. Protein profiling, using microfluidic capillary electrophoresis, provides a rapid (less than 40 minutes), reliable and field-based screening method. Two commonly encountered hoax agents, three Bacillus species (including B. anthracis Sterne strain), two Yersinia species and E. coli were profiled on the Experion™ System (Bio-Rad). Peak detection algorithms were developed for the identification of protein peaks in electropherograms. Boolean logic paths were then employed to predict the electrophoretic pattern of samples. Parameters assessed included variation within and between Experion™ Pro260 chips and the ability to discriminate between samples over time intervals, between operators and between field and laboratory analyses. Classification with optimal Boolean logic paths reported no misclassification with an accuracy of 100% for B. anthracis Sterne strain, B. thuringiensis (powder and culture-based), B. cereus and plain wheat flour. Overall there was 75% correct identification for the eight sample types tested.
Brown, AO, Frankham, GJ, Bond, L, Stuart, BH, Johnson, RN & Ueland, M 2021, 'An overview of risk investment in the transnational illegal wildlife trade from stakeholder perspectives', WIREs Forensic Science, vol. 3, no. 2.
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AbstractThe illegal wildlife trade (IWT) is a lucrative, clandestine trade that endangers animal welfare, damages native biodiversity and undermines the rule of law. Despite enhanced law enforcement focus and increased litigation, the illicit trade of wildlife and wildlife products has continued to flourish. The increase in the IWT can be attributed to a lack of identifiable relationships, risk functions and reward systems specific to each stakeholder in this illicit market. The increase in the IWT indicates that domestic and international regulations are not effective in their intent of preventing the illegal trade of various wildlife species. Without a clear understanding of stakeholder relationships, resources will continue to be wasted on ineffective prevention and detection methods with regards to the IWT. Law enforcement strategies rely on identifying key stakeholders in the IWT as well as their perceived motivations, risks, and relationships. These definitions may provide further insight into the motivations driving these individuals participating in this illicit market and may contribute to more successful interventions. Stakeholders and their associated roles within the IWT have been defined to serve as a tool to understand the various risk/reward utility functions in global markets. This study provides a framework support for policy makers by establishing baseline risk/reward systems for each stakeholder which can be built upon as intelligence surrounding these stakeholders increases.This article is categorized under: Jurisprudence and Regulatory Oversight > Communication Across Science and Law Jurisprudence and Regulatory Oversight > Interdisciplinary Collaboration
Brown, AO, Frankham, GJ, Stuart, BH & Ueland, M 2021, 'Reptile volatilome profiling optimisation: A pathway towards forensic applications', Forensic Science International: Animals and Environments, vol. 1, pp. 100024-100024.
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Reptiles are the most trafficked live taxa in the illegal wildlife trade, in part due to their popularity as an exotic pet. Current methods used to detect these illegally trafficked animals are limited. This study optimised the collection and analysis parameters associated with volatilome collection that will set the foundation for targeted odourant detection methods. This study determined that the dual sorbent type (Tenax® TA and Carbograph 5DT) in combination with 20-min sampling times and 15-min sampling intervals collected the most reproducible reptile volatilome profiles. It was also determined that desorption methods with mid-range desorption flows (20 ml/min), trap temperatures (-15 °C), and mid-range trap desorption (25 ml/min) were most effective in retrieving collected reptile volatilomes. Two-dimensional gas chromatography coupled with time-of-flight mass spectrometry was used for analysis, where combined Rxi-624 Sil MS (mid-polar) first dimension and Stabilwax® (polar) second dimension column sets were selected as the most effective columns for analysing reptile volatilomes. The resultant data collected and analysed using these parameters demonstrated that individual volatilomes from three reptile species were distinct using principal component analysis. In addition, this work highlighted the need for more rigorous statistical methods to determine reptile biomarkers and which compounds most significantly influence volatilome profiles between species.
Chadwick, S, Cvetanovski, M, Ross, M, Sharp, A & Moret, S 2021, 'Comparison of NIR powders to conventional fingerprint powders', Forensic Science International, vol. 328, pp. 111023-111023.
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Fingerprint powders remain one of the most common detection techniques used at the crime scene. However, powder efficiency and contrast can be hindered when applied to highly patterned backgrounds. This problem can be overcome using powders that are luminescent in the near-infrared (NIR) region of the electromagnetic spectrum. Despite being commercially available, those powders have been the focus of only a small number of studies, limited to a few substrates or donors. Their performance and advantages over common techniques are still to be thoroughly investigated. This study aims at assessing the performances of two NIR powder (fpNATURAL 1® and Universal Powder an in-house developed powder) against two conventional powders, a black and a luminescent powder (Sirchie Black, GREENcharge™) under various optical conditions (white light, visible luminescence and NIR luminescence). The powders were compared on four substrates using fingermarks of four different ages from five donors. A total 900 fingermarks were collected for each pairwise comparison. NIR imaging provided good background suppression and a high contrast, however it was shown that conventional powders remained the most effective powdering methods on the substrates tested as sufficient contrast could be achieved under white light or in luminescent mode in the visible region. The results showed that Universal Powder performed similarly to conventional powders, but poor performances were obtained on most substrates with fpNATURAL 1®. Based on the results obtained, it is recommended to use NIR powders only on substrates or conditions where traditional powders are known to perform poorly.
Clases, D, Ueland, M, Gonzalez de Vega, R, Doble, P & Pröfrock, D 2021, 'Quantitative speciation of volatile sulphur compounds from human cadavers by GC-ICP-MS', Talanta, vol. 221, pp. 121424-121424.
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This work demonstrates the first forensic application of GC-ICP-MS for improved investigations of volatile organic compounds originating from a decomposing body. Volatile organic compounds were extracted from the headspace of human remains using sorbent tubes over a total time of 39 days. To account for naturally abundant species, control sites were prepared and sampled accordingly. All samples were spiked with an internal standard to minimise drift effects and errors during sample preparation and further analysis. Compound independent quantification was possible from a single chromatogram with a standard mix containing volatile pesticide compounds representing different mass fractions of target elements for calibration. Phosphorus, sulphur and chlorine were investigated as biologically relevant elements, which potentially form detectable volatile species during decomposition. The limits of detection of these elements in the headspace were 0.7, 5.4 and 1.6 ng/L, respectively. For sulphur, we identified abundant species which increased in concentrations of up to 1310 ng/L in the headspace above the remains. The concentrations were time dependent and show potential as forensic markers to determine post-mortem intervals or decomposition states. The universal quantification, standardisation and the high sensitivity of GC-ICP-MS augments traditional GC-MS analyses.
Clases, D, Ueland, M, Gonzalez de Vega, R, Doble, P & Pröfrock, D 2021, 'Quantitative speciation of volatile sulphur compounds from human cadavers by GC-ICP-MS.', Talanta, vol. 221, pp. 1-8.
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This work demonstrates the first forensic application of GC-ICP-MS for improved investigations of volatile organic compounds originating from a decomposing body. Volatile organic compounds were extracted from the headspace of human remains using sorbent tubes over a total time of 39 days. To account for naturally abundant species, control sites were prepared and sampled accordingly. All samples were spiked with an internal standard to minimise drift effects and errors during sample preparation and further analysis. Compound independent quantification was possible from a single chromatogram with a standard mix containing volatile pesticide compounds representing different mass fractions of target elements for calibration. Phosphorus, sulphur and chlorine were investigated as biologically relevant elements, which potentially form detectable volatile species during decomposition. The limits of detection of these elements in the headspace were 0.7, 5.4 and 1.6 ng/L, respectively. For sulphur, we identified abundant species which increased in concentrations of up to 1310 ng/L in the headspace above the remains. The concentrations were time dependent and show potential as forensic markers to determine post-mortem intervals or decomposition states. The universal quantification, standardisation and the high sensitivity of GC-ICP-MS augments traditional GC-MS analyses.
Clases, D, Ueland, M, Gonzalez de Vega, R, Doble, P & Pröfrock, D 2021, 'Quantitative speciation of volatile sulphur compounds from human cadavers by GC-ICP-MS.', Talanta, vol. 221, p. 121424.
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This work demonstrates the first forensic application of GC-ICP-MS for improved investigations of volatile organic compounds originating from a decomposing body. Volatile organic compounds were extracted from the headspace of human remains using sorbent tubes over a total time of 39 days. To account for naturally abundant species, control sites were prepared and sampled accordingly. All samples were spiked with an internal standard to minimise drift effects and errors during sample preparation and further analysis. Compound independent quantification was possible from a single chromatogram with a standard mix containing volatile pesticide compounds representing different mass fractions of target elements for calibration. Phosphorus, sulphur and chlorine were investigated as biologically relevant elements, which potentially form detectable volatile species during decomposition. The limits of detection of these elements in the headspace were 0.7, 5.4 and 1.6 ng/L, respectively. For sulphur, we identified abundant species which increased in concentrations of up to 1310 ng/L in the headspace above the remains. The concentrations were time dependent and show potential as forensic markers to determine post-mortem intervals or decomposition states. The universal quantification, standardisation and the high sensitivity of GC-ICP-MS augments traditional GC-MS analyses.
Clases, D, Ueland, M, Gonzalez, DVR, Doble, P & Pröfrock, D 2021, 'Quantitative speciation of volatile sulphur compounds from human cadavers by GC-ICP-MS.', Talanta, vol. 221, pp. 1-8.
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This work demonstrates the first forensic application of GC-ICP-MS for improved investigations of volatile organic compounds originating from a decomposing body. Volatile organic compounds were extracted from the headspace of human remains using sorbent tubes over a total time of 39 days. To account for naturally abundant species, control sites were prepared and sampled accordingly. All samples were spiked with an internal standard to minimise drift effects and errors during sample preparation and further analysis. Compound independent quantification was possible from a single chromatogram with a standard mix containing volatile pesticide compounds representing different mass fractions of target elements for calibration. Phosphorus, sulphur and chlorine were investigated as biologically relevant elements, which potentially form detectable volatile species during decomposition. The limits of detection of these elements in the headspace were 0.7, 5.4 and 1.6 ng/L, respectively. For sulphur, we identified abundant species which increased in concentrations of up to 1310 ng/L in the headspace above the remains. The concentrations were time dependent and show potential as forensic markers to determine post-mortem intervals or decomposition states. The universal quantification, standardisation and the high sensitivity of GC-ICP-MS augments traditional GC-MS analyses.
Gupta, A, Corzo, R, Akmeemana, A, Lambert, K, Jimenez, K, Curran, JM & Almirall, JR 2021, 'Dimensionality reduction of multielement glass evidence to calculate likelihood ratios', Journal of Chemometrics, vol. 35, no. 1.
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AbstractDimensionality reduction of multivariate elemental concentrations of glass is reported for computing likelihood ratios (LRs). The LRs calculated using principal component analysis (PCA) and a post hoc calibration steps result in very low (<1%) false inclusions when comparing glass samples known to originate from different sources and very low (<1%) false exclusions when comparing glass samples known to originate from the same source. The LRs calculated using the novel PCA approach are compared with previously reported LRs calculated using a more computationally intensive Multivariate Kernel (MVK) model followed by a calibration step using a Pool Adjacent Violators (PAV) algorithm. In both cases, the calibrated LRs limited the magnitude of the misleading evidence, providing only weak to moderate support for the incorrect hypotheses. Most of the different pairs that were found to be falsely included were explained by chemical relatedness (same manufacturer of the glass sources in very close time interval between manufacture). The computation of LRs using dimensionality reduction of elemental concentrations using PCA may transfer to other multivariate data‐generating evidence types.
Kanodarwala, FK, Leśniewski, A, Olszowska-Łoś, I, Spindler, X, Pieta, IS, Lennard, C, Niedziółka-Jönsson, J, Moret, S & Roux, C 2021, 'Fingermark detection using upconverting nanoparticles and comparison with cyanoacrylate fuming', Forensic Science International, vol. 326, pp. 110915-110915.
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This paper reports the synthesis of high-quality upconverting nanoparticles (UCNPs) - sodium yttrium tetrafluoride doped with ytterbium and erbium (NaYF4:Yb,Er) with a silica shell and capped with phenyl functional groups. The main goal of this research was to design tailor-made UCNPs for fingermark detection, to test and validate a nanoparticle-based detection technique and to compare their performance against a benchmark method to assess potential implementation in routine practice by law enforcement agencies. The water-based UCNPs solution was applied to natural fingermarks on a number of substrates. This is the first ever systematic comparative study between UCNPs and a benchmark fingermark detection technique - cyanoacrylate fuming (CAF) followed by luminescent dye staining. Fingermark detection effectiveness was studied by treating 300 latent fingermark specimens on aluminium foil, polyethylene, polypropylene and glass slides. It was concluded that, on average, CAF performed better across the substrates tested. Nevertheless, UCNPs can be advantageous for fingermark detection on multicoloured, patterned or luminescent substrates due to their unique optical properties. There are, however, shortfalls associated with their synthesis and use that need to be addressed before they can be considered for operational purposes.
Kanodarwala, FK, Moret, S, Spindler, X, Lennard, C & Roux, C 2021, 'Novel upconverting nanoparticles for fingermark detection', Optical Materials, vol. 111, pp. 110568-110568.
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© 2020 This paper reports the synthesis of high-quality upconverter nanoparticles (UCNPs) – sodium yttrium tetrafluoride doped with ytterbium and erbium (NaYF4:Yb,Er) with a silica shell and capped with carboxyl functional groups. The effect of different synthesis methods on the silica capping has been studied in detail. The main goal of this research was to design tailor-made UCNPs for fingermark detection and to validate a NP-based detection technique that is user-friendly, cost-effective and can be implemented in routine practice by law enforcement agencies. UCNP powders and solutions were used as a proof-of-concept to detect latent fingermarks on an aluminium foil substrate. This study not only highlights the potential use of UCNPs as a fingermark detection method but also identifies a number of shortfalls in its application that need to be addressed before such an approach could be implemented as a valid detection technique.
Katsnelson, A 2021, 'A Conversation with Maiken Ueland', ACS Central Science, vol. 7, no. 9, pp. 1451-1453.
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Maitre, M, Chiaravalle, A, Horder, M, Chadwick, S & Beavis, A 2021, 'Evaluating the effect of barrel length on pellet distribution patterns of sawn-off shotguns', Forensic Science International, vol. 320, pp. 110685-110685.
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Mohanty, M, Zhang, M, Asghar, MR & Russello, G 2021, 'e-PRNU: Encrypted Domain PRNU-Based Camera Attribution for Preserving Privacy', IEEE Transactions on Dependable and Secure Computing, vol. 18, no. 1, pp. 426-437.
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IEEE Photo Response Non-Uniformity (PRNU) noise-based source camera attribution is a popular digital forensic method. In this method, a camera fingerprint computed from a set of known images of the camera is matched against the extracted noise of an anonymous questionable image to find out if the camera had taken the anonymous image. The possibility of privacy leak, however, is one of the main concerns of the PRNU-based method. Using the camera fingerprint (or the extracted noise), an adversary can identify the owner of the camera by matching the fingerprint with the noise of an image (or with the fingerprint computed from a set of images) crawled from a social media account. In this article, we address this privacy concern by encrypting both the fingerprint and the noise using the Boneh-Goh-Nissim (BGN) encryption scheme, and performing the matching in encrypted domain. To overcome leakage of privacy from the content of an image that is used in the fingerprint calculation, we compute the fingerprint within a trusted environment, such as ARM TrustZone. We present e-PRNU that aims at minimizing privacy loss and allows authorized forensic experts to perform camera attribution. The security analysis shows that the proposed approach is semantically secure.
Olander, A, Lawson, CA, Possell, M, Raina, J-B, Ueland, M & Suggett, DJ 2021, 'Comparative volatilomics of coral endosymbionts from one- and comprehensive two-dimensional gas chromatography approaches', Marine Biology, vol. 168, no. 5, p. 76.
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Volatilomics, the examination of all biogenic volatile organic compounds (BVOCs) emitted by an organism or system, holds potential as a novel screening tool for taxonomy, fitness, and ecological functioning. Volatilomics has been largely applied to terrestrial environments, but highly productive coastal marine systems, which are major sources of specific BVOCs, such as dimethyl sulfide, have been largely neglected. Volatilomic measurements are highly method-dependent, with different instrumentation impacting the diversity of identified BVOCs—therefore, understanding these biases is critical to reconcile studies. Here, we investigated BVOCs emitted by two species of coral endosymbiotic microalgae (Symbiodinium tridacnidorum and Durusdinium trenchii) using gas chromatography–mass spectrometry (GC–MS) and comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC × GC–TOFMS). Seven chemical classes were detected by both instruments, the most common being aromatic hydrocarbons. However, GC × GC resolved seven times more BVOCs than GC–MS (290 vs. 40), with a higher proportion of compounds tentatively identified (173 vs. 14). Notably, nine chemical classes were exclusively identified by GC × GC, including alkane, alkene, aldehyde, ester, and nitrile BVOCs—each potentially fulfilling undescribed functions in marine organisms. The microalgal species investigated shared a large proportion of BVOCs, and this result was consistent across instruments (97 and 98% shared compounds via GC × GC and GC–MS, respectively), suggesting consistent retrieval of general patterns between instruments. This method comparison is the first of its kind in marine systems and confirms the greater analytical power of GC × GC, required to help resolve complex BVOC emissions and the identification of their roles in marine systems.
Popovic, A, Morelato, M, Roux, C & Beavis, A 2021, 'Interpreting the link value of similarity scores between illicit drug specimens through a dual approach, featuring deterministic and Bayesian frameworks', Forensic Science International, vol. 319, pp. 110651-110651.
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Illicit drug trafficking and in particular amphetamine-type stimulants continue to be a major problem in Australia. With the constant evolution of illicit drugs markets, it is necessary to gain as much knowledge about them to disrupt or reduce their impact. Illicit drug specimens can be analysed to generate forensic intelligence and understand criminal activities. Part of this analysis involves the evaluation of similarity scores between illicit drug profiles to interpret the link value. Most studies utilise one of two prominent score evaluation approaches, i.e. deterministic or Bayesian. In previous work, the notion of a dual approach was suggested, which emphasised the complementary nature of the two mentioned approaches. The aim of this study was to assess the operational capability of a dual approach in evaluating similarity scores between illicit drug profiles. Utilising a practical example, link values were generated individually from both approaches, then compared in parallel. As a result, it was possible to generate more informed hypotheses, relating to specimen linkage, due to the greater wealth of information available from the two approaches working concurrently. Additionally, it was shown that applying only one approach led to less information being generated during analysis as well as potentially important links between illicit drug specimens being missed.
Prasad, E, Barash, M, Hitchcock, C, van Oorschot, RAH, Raymond, J, McNevin, D & Gunn, P 2021, 'Evaluation of soaking to recover trace DNA from fired cartridge cases', Australian Journal of Forensic Sciences, vol. 53, no. 5, pp. 512-522.
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© 2020, © 2020 Australian Academy of Forensic Sciences. The recovery of trace DNA from cartridge cases is of common interest across many jurisdictions. Soaking offers improved profiling success rates over traditional methods. We evaluated the effects of firing, calibre, and metal composition on controlled and handled DNA samples utilizing a soaking method. Our results show that firing decreases the quantities of DNA recoverable from cartridge cases and higher quantities of DNA are recoverable from nickel ammunition compared to brass. In spiked samples, calibre of ammunition had no significant effect on DNA recovery. Despite slight to moderate DNA degradation and variable profiling success rates, spiked unfired and fired nickel cartridges resulted in more usable profiles than brass cartridges. These findings can aid in triaging the types of ammunition subjected to DNA testing.
Qashlan, A, Nanda, P, He, X & Mohanty, M 2021, 'Privacy-Preserving Mechanism in Smart Home Using Blockchain', IEEE Access, vol. 9, pp. 103651-103669.
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The IoT, or Internet of Things has been a major talking point amongst technology enthusiasts in recent years. The internet of thing (IoT) has been emerged and evolved rapidly, making the world's fabric around us smarter and more responsive. The smart home uses one such transformation of IoT, which seems to be the wave of the future. However, with the increasing wide adoption of IoT, data security, and privacy concerns about how our data is collected and shared with others, has also risen. To solve these challenges, an approach to data privacy and security in a smart home using blockchain technology is proposed in this paper. We propose authentication scheme that combines attribute-based access control with smart contracts and edge computing to create a secure framework for IoT devices in smart home systems. The edge server adds scalability to the system by offloading heavy processing activities and using a differential privacy method to aggregate data to the cloud securely and privately. We present several aspects of testing and implementing smart contracts, the differential private stochastic gradient descent algorithm, and system architecture and design. We demonstrate the efficacy of our proposed system by fully examining its security and privacy goals in terms of confidentiality, integrity, and availability. Our framework achieves desired security and privacy goals and is resilient against modification, DoS attacks, data mining and linkage attacks. Finally, we undertake a performance evaluation to demonstrate the proposed scheme's feasibility and efficiency.
Roux, C & Weyermann, C 2021, 'From Research Integrity to Research Relevance to Advance Forensic Science', Forensic Sciences Research, vol. 6, no. 4, pp. 292-294.
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Roux, C, Willis, S & Weyermann, C 2021, 'Shifting forensic science focus from means to purpose: A path forward for the discipline?', Science & Justice, vol. 61, no. 6, pp. 678-686.
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Forensic science is facing a persistent crisis that is often addressed by organizational responses, with a strong focus on the improvement and standardisation of means and processes. However, organisations and processes are highly dependent on the political, economical and legal structures in which they operate. This may explain why most proposed solutions had difficulties in addressing the crisis up to now, as they could hardly be applied transversally to all forensic science models. Moreover, new tools and technologies are continuously developed by a quasi-infinite number of different scientific disciplines, thus leading to further diversity and fragmentation of forensic science. In this paper, it is proposed to shift the focus from means to purpose and consider forensic science current challenges in terms of discipline, before addressing organisations’ specific issues. As a distinct discipline, forensic science can refocus research and development on shared principles and purposes, such as reconstructing, monitoring, and preventing crime and security issues. This focus change will facilitate a better understanding of the trace as the object of study of forensic science and eventually lead to a more impactful and long-lasting effect. This approach will also foster the development of a forensic science culture (instead of a primarily technological culture) unified by purpose rather than means through more relevant education and research.
Taudte, RV, Roux, C, Bishop, DP, Fouracre, C & Beavis, A 2021, 'High-throughput screening for target compounds in smokeless powders using online-SPE tandem mass spectrometry', Australian Journal of Forensic Sciences, vol. 53, no. 1, pp. 16-26.
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© 2019, © 2019 Australian Academy of Forensic Sciences. The detection and quantification of compounds present in smokeless powders plays an important role in various fields such as environmental and forensic science. Often, time and labour consuming sample preparation techniques such as solid phase extraction (SPE) are required to facilitate either pre-concentration or sample clean-up with complex matrices. This paper describes the first application of the completely automated online SPE system RapidFire® connected to a triple quadrupole mass spectrometer for smokeless powder/gunshot residue analysis. The optimized method involved sample loading during 2000 ms using UP water (0.1% formic acid) at a flowrate of 1.25 mL/min on a Type C C18 cartridge followed by elution of the target compounds for 3000 ms using IPA (0.1% formic acid) at 0.75 mL/min. Target compounds were detected in soil (DPA, 2-NDPA, EC, NG, 2,4-DNT) and cotton swabs (NG) in only 8 seconds per sample with detection limits of 0.223 ppm (DPA), 0.104 ppm (2-NDPA), 0.0949 ppm (EC), 0.187 ppm (NG) and 0.128 ppm (2,4-DNT). The presented method showed promising results for the analysis of five target analytes in soil samples. Further optimisations can extend the analysis to other sample matrices and include more analytes potentially present in smokeless powders and GSR.
Ueland, M, Collins, S, Maestrini, L, Forbes, SL & Luong, S 2021, 'Fresh vs. frozen human decomposition – A preliminary investigation of lipid degradation products as biomarkers of post-mortem interval', Forensic Chemistry, vol. 24, pp. 100335-100335.
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Traditionally, the post-mortem interval (PMI) is determined using methods such as forensic entomology or forensic pathology, however, these techniques are often limited to a particular post-mortem window of up to 72 – 120 h after death. In this study, lipids extracted from decomposing human tissue were investigated as potential soft-tissue biomarkers of PMI. Tissue samples were collected from two whole human donors (n = 2), one frozen and one fresh, placed at the Australian Facility for Taphonomic Experimental Research (AFTER) over the course of 69 days post-placement. These samples were analysed using gas chromatography coupled with tandem mass spectrometry (GC–MS/MS), demonstrating statistically significant differences for most fatty acid analytes and further highlighting the well-known stability of sterol compounds over time. Differences were observed between the fresh and frozen donor, with the fresh donor displaying more distinct stages of decomposition. Chemical differences between the donors were more distinct in the fatty acids than the sterols. The fatty acid profiles over time were further investigated and target analytes comprising saturated fatty acids (stearic acid and palmitic acid) and unsaturated fatty acids (oleic acid and linoleic acid) were found to be of particular importance due to their potential as indicators of PMI.
Ueland, M, Harris, S & Forbes, SL 2021, 'Detecting volatile organic compounds to locate human remains in a simulated collapsed building', Forensic Science International, vol. 323, pp. 110781-110781.
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The occurrence of mass disasters has increased worldwide due to changing environments from global warming and a heightened threat of terrorism acts. When these disasters strike, it is imperative to rapidly locate and recover human victims, both the living and deceased. While search and rescue dogs are used to locate the living, cadaver detection dogs are typically tasked with locating the dead. This can prove challenging because commingling of victims is likely to occur during disasters in populated areas which will impact the decomposition process and the resulting odour produced. To date, there has been no research to investigate the process of human decomposition in a mass disaster scenario or to understand which compounds are detectable by cadaver detection dogs. Hence, the current study investigated the human decomposition process and subsequent volatile organic compound (VOC) production in two simulated building collapse scenarios with six human donors placed in each scenario. The human remains were only recovered after a period of one month, during which time VOC samples were collected and analysed using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry. A considerable degree of differential decomposition was observed upon recovery of the human remains, which was carried out as a part of a police disaster victim recovery training exercise. The location of the bodies in the disaster area was found to impact the decomposition process. The VOC profile was found to correlate with the decomposition process. Fifteen days following the simulated disaster, the VOC profile changed showing that a detectable change in the decomposition process had occurred. Overall, the changing VOC profile can inform the training of cadaver detection dogs for these unique scenarios.
Watherston, J, Watson, J, Bruce, D, Ward, J & McNevin, D 2021, 'Efficient DNA Profiling Protocols for Disaster Victim Identification', Forensic Sciences, vol. 1, no. 3, pp. 148-170.
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Advances in forensic biology have increased the options for the collection, sampling, preservation and processing of human remains for DNA-based identification. Combined with a plethora of commercial DNA testing kits that are far more forgiving of inhibited and degraded samples, efficient DNA approaches to post-mortem samples are explored here for DNA-based identification of compromised human remains. Approaches which preserve sample and reduce analytical turnaround times whilst saving resources also have the potential to expedite the identification process, to provide answers to grieving families sooner, or to provide leads in a criminal investigation. Targeting sample types that are minimally-invasive and do not require extensive preparation and testing protocols also has benefit for disaster victim identification (DVI) by facilitating field sampling. We have assessed minimally-invasive and simple to collect sample types compatible with minimal pre-treatment and efficient DNA profiling approaches. Incubating nail, distal phalanges and whole digits in 500 µL of PrepFiler™ Lysis Buffer for 2 h was an efficient and simple method, limiting or removing sample preparation. A reduced 15 min incubation also yielded DNA profiles suggesting a shorter incubation may lyse sufficient DNA. Preservative solutions offer an even simpler process in some cases. Furthermore, the efficient approaches described in this study offer storage solutions and are compatible with backend automated processing. This study will inform further research to develop and optimise efficient protocols. These DNA approaches should not be pursued for every sample; more compromised samples may best be submitted to the laboratory for more effective extraction and genotyping.
Watson, CJ, Ueland, M, Schotsmans, EMJ, Sterenberg, J, Forbes, SL & Blau, S 2021, 'Detecting grave sites from surface anomalies: A longitudinal study in an Australian woodland', Journal of Forensic Sciences, vol. 66, no. 2, pp. 479-490.
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AbstractForensic investigations of single and mass graves often use surface anomalies, including changes to soil and vegetation conditions, to identify potential grave locations. Though numerous resources describe surface anomalies in grave detection, few studies formally investigate the rate at which the surface anomalies return to a natural state; hence, the period the grave is detectable to observers. Understanding these processes can provide guidance as to when ground searches will be an effective strategy for locating graves. We studied three experimental graves and control plots in woodland at the Australian Facility for Taphonomic Experimental Research (Sydney, Australia) to monitor the rate at which surface anomalies change following disturbance. After three years, vegetation cover on all grave sites and control plots had steadily increased but remained substantially less than undisturbed surroundings. Soil anomalies (depressions and cracking) were more pronounced at larger grave sites versus the smaller grave and controls, with leaf litterfall rendering smaller graves difficult to detect beyond 20 months. Similar results were observed in two concurrent burial studies, except where accelerated revegetation appeared to be influenced by mummified remains. Extreme weather events such as heatwaves and heavy rainfall may prolong the detection window for grave sites by hindering vegetation establishment. Observation of grave‐indicator vegetation, which exhibited abnormally strong growth 10 months after commencement, suggests that different surface anomalies may have different detection windows. Our findings are environment‐specific, but the concepts are applicable globally.
Weyermann, C & Roux, C 2021, 'A different perspective on the forensic science crisis', Forensic Science International, vol. 323, pp. 110779-110779.
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Recurrent mentions of a forensic science crisis are reported in the literature. Some 15 years ago, the discussion was focused on the backlog problem. Other issues have been regularly debated since then, including the risk of error, need for independence, importance and risk of contextualisation, increasing fragmentation into separate processes and specialisations. Proposed solutions to solve one problem often led to other issues in other parts of the process. This paper attempts to address the apparent crisis using a different perspective, through a comparison with established disciplines, namely material science, medicine and historical science. The comparison with material science shows that, despite the varied organisational and legal models and the interdisciplinary nature of the field, a common element to all forensic science endeavours exists: the trace. A greater focus on the trace might thus help the development of a holistic approach in forensic science. The comparison with medicine demonstrates that, through the overall process, the main risk shifts from the risk to overlook important hypotheses or traces at the beginning of the process (e.g. problems in the detection of traces/symptoms and formulation of hypotheses) to the risk of supporting the wrong hypothesis at the end of the process (e.g. erroneous test of the hypotheses/diagnostic). Further, in medicine, symptoms are rarely evaluated in isolation, while traces are often evaluated separately. By analogy, epidemiology illustrates forensic science's critical role in preventing crime through forensic intelligence, supporting a more extensive and more collaborative application of forensic science in security issues. The comparison with historical science also indicates that a single trace (i.e. the observed effect) is rarely sufficient to reason on its cause. Retrodiction (abduction) is proposed as an alternative reasoning approach to reconstruct events from the past based on signs uncovered...
Yuen, ZW-S, Srivastava, A, Daniel, R, McNevin, D, Jack, C & Eyras, E 2021, 'Systematic benchmarking of tools for CpG methylation detection from nanopore sequencing', Nature Communications, vol. 12, no. 1.
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AbstractDNA methylation plays a fundamental role in the control of gene expression and genome integrity. Although there are multiple tools that enable its detection from Nanopore sequencing, their accuracy remains largely unknown. Here, we present a systematic benchmarking of tools for the detection of CpG methylation from Nanopore sequencing using individual reads, control mixtures of methylated and unmethylated reads, and bisulfite sequencing. We found that tools have a tradeoff between false positives and false negatives and present a high dispersion with respect to the expected methylation frequency values. We described various strategies to improve the accuracy of these tools, including a consensus approach, METEORE (https://github.com/comprna/METEORE), based on the combination of the predictions from two or more tools that shows improved accuracy over individual tools. Snakemake pipelines are also provided for reproducibility and to enable the systematic application of our analyses to other datasets.
